1. Field of the Invention
This invention relates to a sprayer device used in the dispensing of at least one but preferably two liquids, such as the components of a fast-setting adhesive aerosol.
2. Description of the Prior Art
A fast-setting two-component adhesive is an adhesive compound that cures within seconds of the components being mixed together. Such fast-setting two-component adhesives have many applications, including use as tissue adhesives for a number of potential medical applications. Such potential medical applications include closing topical wounds, delivering drugs, providing anti-adhesion barriers to prevent post-surgical adhesions, and supplementing or replacing sutures or staples in internal surgical procedures. To be suitable for medical applications such tissue adhesives must be fast-curing, have good mechanical strength, be able to bind to the underlying tissue and pose no risk of infection.
The components of such fast-setting two-component adhesives must be mixed either at the site of application or immediately (i.e., typically within a few seconds) before application.
One conventional technique employs a static mixer connected to the discharge ends of the containers holding the liquid components and moving these components through a serpentine passage to the tissue being treated. The components are mixed in the serpentine passage before the adhesive exits the passage. Representative of such conventional static mixer are those devices sold by Med Mix Systems AG, Rotkreuz, Switzerland and Mix Tek System LLC, New York, N.Y. U.S. Pat. No. 5,595,712, assigned to the assignee of the present invention, also discloses a static mixing device employing a serpentine passage within a planar structure.
Prior art static mixers are believed disadvantageous for use in any medical application which requires intermittent application of adhesive. If flow of the adhesive through the mixer is interrupted, even momentarily, the mixed components increase in viscosity. This increase in viscosity, known as gelling, may occur so rapidly that the mixer passage becomes clogged, thus preventing the resumption of flow of the adhesive.
Besides the static mixers, dynamic mixers such as powered impellers and magnetic stir bars have been used. However these devices are costly and cumbersome and not particularly amenable to medical use as they may damage the adhesive by over-mixing.
Hand-held mixing devices that entrain the liquid components in a gas stream are also known. Some of these devices join the liquid components in a common discharge line prior to application to the site and are thus subject to the same risk of gelling as in a static mixer.
Other hand-held mixing devices use separate discharge lines for each of the liquid components. In these cases a gas entrains each liquid and carries the liquid through a separate discharge line. However, when the device is used with relatively high viscosity liquids of the type used in some adhesives (ranging in viscosity from about ten to one thousand centipoise) the liquid deposits appear on the deposit site as segregated clumps which are not well mixed.
Neither of these gas powered devices are self-contained since the gas used in both hand-held devices is supplied through a tethered connection to a fluid source. Such a tethered arrangement is believed disadvantageous because it limits the ease with which an operator can handle the device.
Accordingly, in view of the foregoing there is believed to be a need for a self-contained, hand-held dispensing device capable of delivering two well-mixed liquid components directly to a desired site while avoiding the clogging problems of prior art devices.